<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<form action="/" method="post">
  用户名 :<input type="text" name="username" /> <br>
  密码 :<input type="text" name="password" /> <br>
  <button type="submit"> 提交</button>
</form>
</body>
</html>